Needle



d 1958 H. G. LAUTERBACH 2,357,650

NEEDLE Filed May 4, 1954 2 Sheets-Sheet l kw ii INVENTOR Herbert G. Lauferbach ATTORNEY Oct. 28, 1958 H. e. LAUTERBACH 2,357,650

NEEDLE Filed May 4, 1954 2 Sheets-Sheet 2 4 INVENTOR Herberf G. Lauferbach ATTORNEY United States Patent NEEDLE Herbert G. Lauterbach, Wilmington, Del., assignor to E. l. du Pont de Nemours and Company, Wilmington, Del., a corporation of Delaware Application May 4, 1954, Serial No. 427,465

7 Claims. (Cl. 284) This invention relates to a needle. More particularly it relates to a novel needle particularly useful in the felting and fulling arts. 7

In accordance with the present invention a novel needle which has an irregular profile is provided. It will be referred to hereinafter as a rasping-profile needle. By a rasping-profile is meant that an elevational view of the needle discloses at least one abrupt, hookless break, i. e., a notch or a protuberance having a substantially smooth surface, in the continuity of its edge. By abrupt is meant that the extent of the profile discontinuity along the longitudinal axis of the needle is no more than about five or six times the extent of its discontinuity normal to the said longitudinal axis. By a hookless break is meant a discontinuity of such shape that as the tangent to the discontinuity is progressed in either direction from the point wherein it is parallel to the longitudinal axis of the needle, it will never change more than about 90 in any one direction without disrupting tangential contact. The term tangent includes a line or plane contacting a position on a straight line portion of the discontinuity as well as the common meaning of tangent which includes a straight line or plane in contact with a point or curved surface or a curved line or plane in contact with a straight surface. that as the line or plane follows the contour of the discontinuity to positions tangential to the discontinuity, whether tangential to straight lines or curved surfaces, it will sweep out an arc of no more than about 90 degrees. This needle is useful in the fulling process described in U. S. application, Serial No. 415,196, filed March 10, 1954, in the name of George Leslie Moler. It is also useful in a process for forming a coherent, nonwoven, felt-like product by needling a loose batt of a fibrous mass containing a substantial proportion of retractable synthetic filaments, thereby forcibly orienting some of the retractable filaments into a position substantially perpendicular to the ultimate faces of the product and thereafter retracting the filaments by appropriate treatment with heat, swelling agent or the like as described in U. S. application No. 312,067, filed September 29, 1952, in the name of Herbert G. Lauterbach, and now abandoned.

It is an object of the present invention to provide a novel needle useful in the textile arts.

Another object is to provide a rasping-profile needle, and a process for making such a needle.

Another object is to provide a needle useful in the fulling of natural and synthetic woven and knitted fabrics.

Another object is to provide a needle useful in the felting of retractable synthetic filaments.

These and other objects will become apparent in the course of the following specification and claims.

The details of the present invention will be more readily understood by reference to the following drawings and description.

By the term progressed is meant- Figure 1a is a fragmentary view of the blade of the needle of Figure l exemplifying various dimensions;

Figure 2 is an illustration of a rasping-profile needle of the present invention prepared from the needle of Figure l;

Figure 2a is a fragmentary view of the blade of the needle of Figure 2 exemplifying various dimensions;

Figure 3 shows a needle containing barbs in a reverse direction to those upon the needle of Figure 1;

Figure 4 illustrates a rasping-profile needle prepared from the barbed needle of Figure 3. i

Figures 5 to 16 inclusive are fragmentary elevations of a rasping-profile needle illustrating variations in the nature of the profile discontinuity within the definition of an abrupt, hookless break.

Figure 5 is a fragmentary elevation of a rasping-profile needle wherein the abrupt, hookless break is a sharp protuberance.

Figure 6 shows a needle profile containing a sharp notch. I

Figure 7 illustrates a combination of a sharp notch and a sharp protuberance. I

Figure 8 exemplifies a sharp protuberance and a rounded notch.

Figure 9 is a needle profile containing a rounded protuberance. g s

Figure l0is a needle profile wherein the notch is rounded.

Figure 11-is a view of a'needle profile with a cont-bination of a rounded protuberance and a rounded notch.

Figure 12 shows a needle combining a rounded protuberance and a sharp notch. j

Figure 13 is a view of along sharp notch in a needle profile.

Figure 14 illustrates a long sharp protuberance in a needle profile.

Figure 15 exemplifies a needle having a long rounded notch.

Figure 16 is a view of a rasping-profile needle wherein a rounded protuberance containing a' sharp notch pro vides profile discontinuity. 1

Referring particularly to Figure '1, this is an elevation I of a barbed needle of the prior art; It will be apparent Figure 1 is an illustration of a commercially available barbed needle;

that as the tangent to the notch (i. e., the tangent'at the apex of the notch angle) is progressed from a point where it is parallel to the longitudinal axis of the needle, around the discontinuity. toward the anchoring end of the needle, it describes an angle of substantially more than Note also that progression of the tangent from the tip of the protuberance where it is parallel to the longitudinal axis toward the needle point causes an angle substantially greater than 90 to be described. This irregularity is in the form of a hook. Neither this needle nor that of Figure 3, therefore, is within the definition of a rasping-profile needle. 1

Figures 2 and 4 each illustrate a rasping-profile needle. The break in continuity is abrupt and hookless. Figures 5 to 16 inclusive illustrate various suitable profile continuity breaks within the definition of a rasping-profile.

The following examples are cited to illustrate the invention. They are not intended to limit it in any manner. The barbed needles of Examples 3 and 8 were obtained from the Textile Machine Works of Reading lennsyb vania. The other barbed needles of Examples ,1 to -10 inclusive were acquired fromthe Torrington Company of Torrington, Connecticut. Each of the barbed needles have triangular cross-sections along their blades. In thesystern of needle designation the figures represent thefollowing dimensions: H

Butt x middle section it blade x overall length. ;,-The unit of length is inches. All other dimensions a {e in terms of wire gauge. The blade gaiige is determined be fore triangulation. The effective cross-sectional dimen- I pegpendicplarly: from. the continuous profile due to a batt area increases about 25%. The needle punched batt is immersed in boiling water for 2 minutes; It shrinks about 50% in area. The felt is dried. It has a final thickness of 0.370 inch and weighs 6.2 pounds per square yard. Its longitudinal tensile strength is 1,580 pounds per square inch while its splitting resistance is 59 pounds per two inc h width. The product has a good appearance with but few visible needle marks.

protuberance. The dimension B is the maximum'varia- It is particularly useful in felt applications where unusual ttion in inches measured perpendicularly fromth'e constrength is required.

tinuous profile due to a notchuThe anglectis the angle b. y.the, lines drawn from the upper and lower Example points 'of profile continuity'tothe deepest pointzwithin h notch! The qi i arefliuustr'ated i pi The needle loom 1s equipped with the unctched needles la and 2a. In each example,.1 125;needles are suspended 15 of Example The P W of Example 11 P 1N pgimldpwn withlonlyfl'm blades submerged in 4400 After the 20 passes the needled batt decreases in density q, p, g tjjQ, hydrochloric acid (in Water) i to the point that a felt can no longer be produced. -..3i?Q .G-fiffic dperlueedle. ,A glass'tray serves The best felt made with these needles 1s shrunkafter to hold the acid. Unless otherwise' noted, ;fresh acid p p e u8 e P on each substituted about every 2y ;h urg, In e ha e h 20 It is 0.5 inch thick, weighs 5.9 pounds per square' yard, a so ons are at rgorn 'temperature and u'nagifated, ZThe has a tensile strength of 630 pounds (per square lnchland blades are spaced sufficiently to avoid contact with one a splitt ng reslstance of pounds per twolnch width. an other ;After etching the needles are rinsed .with Water In add tion to its relatlvely poor strength characterto remove acid and thereafter dried, istics, this felt contains visible needle marks and exhibits Before Etching Etching After Etching Ex. Needle .zr Time 1 1 f ncy-1. v I

A n D a A B 1) a Degrees Degrees 15x18x25x3 .0048 .0076 I .039 .66 7 o .0007 .020 3 142 (Reg.Bnrb).

ameasl .0048 .0076 .039 00 14 0 .0025 .012 154 15 x18xB25it53l 5 (Re- .0038 ..0070 .039 l 85 0 .0038 .021 135 x1sx25x3 4 .0048 .0076 .040 77 7 0 .0070 1025 130 lbxlh sxal .0057 .0115 .050 74 7 0 .0103 .032 h 128 .0065 .0126 .050 as 7 .0019 .0115 .043 9a 1 (Close Barb).

15x18x30x3% .0048 .0007 .032 84 7 o .0057 .023 121 I (Reg. Barb). 1 8-- 15x-lSx30x3% 0 .0038 .012 05 7 0 .0038 .007 104 (Reg. Barb). 9--.-. 15g1D25xiRegs .0038 .0070 .037 71 7 ..0015 .0007 .022 120 i 10-.-. sanias'i .0048 .0076 .039 as 4% 0 .0072 .028 .133

7 m Rasping-prbfile needles prepared as described above are tufts of fibers vertically oriented on the surface opposite particularly valuable in the production of 'a coherent, nonto that in Which'the' needles are last introduced. wove'n, felt-like product from a loose batt/of a fibrous mass containing a substantial proportion of retractable E amp 13 f'synthetic filamentas described in U. -S. applicationNo. l 312,067.; This process is illustrated in Examples 11 to 15 The needle loom 15 equipped wlth fi etched nfidlcs inclusive which" follow. In each example about 1400 A batt Pflcarded'layers. fl necdles are mounted on the needle' boards of 21 36 inch p g ng, 4.8 pounds p SquareQyard IS fsrmed .Q Company needwlbom from seven. denier. per filament, three lnchstaple polymnstattzso revolutions per minute; feed ethylene terephthalate, prepared as .descrlbed'm Example "vancesiwhile the'needles are drawn clear of it atthe 111". The f to for five rate.,of,0.285 inch per needle oscillation. The properc- P resultmg abOUt'SZS needle punichmgs P 1"? ities of the felts'p'roduc'ed, namely, thickness in inches, 03 Inch The needied batt 1s 40% m by Passing tensile streng'th (longitudinal or transverse) inpoi1't1ds per through a hot atqzoo for 5 The square inch and'splitting resistance in pounds per twofelt Product wmgohs elght Squaw yard' ,A inch width, are determined according to A."S. T. M. Pressing at 120 for WO mmutesunder a p u .;Desiguation; D461-53 entitled 'Standard 'Methods of Oifive hundred P0911115 Per Square It has an average Tcstifig r 1 1 1 thickness of 0.340 ll'lCh. The average splitting resistance 8 Example 11 is 21.3 pounds per two inch width; Longitudinal tensile w strength is 940 pounds .per square inch: The product is 7 T hq .=.s1. 99m. S flw l Fifi PF dense and contains but few visible needle marks? It is Qnlfle 3- qusntlty of three denier, SP P Q Y useful as a glass polishing 'felt. 'cri pable polyethylene terephthalate filament is prepared a ruding through a s pinneret and drawing in' an' air Example 14 ct asd1sclose'djn U. S. Patent 2,604,689 to Hebeler. 1

filaments are cut into 2 /2 inch staple fibers'and The needle loom as equipped in Example 13 is fed fivithout Lr elaxing are cardedas in conventional textile the batt of Example 13 for a total of 31 passes (about .l prations. "A batt thi'rty inches wide, is formed from 3255 punchings per square inch). The needled batt is thexcarded layers to a depth of about 3 inches and shrunk in boiling Water as taught previously. It'is not jfwelghlng 3.1 pounds per square yard. The batt is fed pressed. The resulting feltweighs 9.6 pounds per square through the needle loomfor a total of 20 passes,- the yard and is 0.50 inch thick. It hasasplitting resistance :batt being turnedoyerafter each pass. It receives about of 68 pounds per two inch width. The longitudinal 2100 punchingspersquare inch. During this stepthe tensile strength is in excess of 1000 pounds per square inch. This thick felt of high density is useful as a polishing felt.

Example 15 The needle loom is equipped with the etched needles of Example 1. A batt of carded layers is formed containing about 75% 3 denier per filament 3 inch staple and about 25% 6 denier per filament 3 inch staple polyethylene terephthalate. The batt is about 1 inch deep and weighs about 3 ounces per square yard. It is passed through the loom 24 times (an average of about 2520 punchings per square inch). It is shrunk 58% by immersion in boiling water for 1 minute. A lightweight felt is formed weighing about 7 ounces per square yard. It has a transverse tensile strength of 600 pounds per square inch, a longitudinal tensile strength of 700 pounds per square inch and a thickness of 0.045 inch. It is suitable for use in skirts and other apparel due to its crease resistance, bending length and liveliness.

The use of the rasping-profile needle as described herein in the preparation of felt-like products in the manner illustrated above permits as much as a ten-fold increase in the number of penetrations per square inch which are possible without weakening the final product than is" possible with the barbed needle of the prior art. The increase in penetrations results in a stronger, more uniform and better appearing product. This is believed due to the increased and more homogeneous entanglement of the vertically oriented fibers. Thus thinner products of acceptable quality may be formed using the raspingprofile needle than was previously possible. Furthermore, in the production of thick felts, less needle breakage is observed with the needle of the invention as compared with a barbed needle. Not only is there a reduction of needle mark size in the product when the rasping-profile needle is employed, but surface tufts, as was described in Example 12 are eliminated.

The etched needles of the present invention are also valuable in the fulling of woven and knitted fabrics by the process taught in U. S. application 415,196 filed March 10, 1954, in the name of George Leslie Moler. In that process woven and knitted fabric is fulled by subjecting it to multiple needling, i. e., a recurrent piercing and withdrawing of a needle of special characteristic and including a rasping-profile needle until migration of fibers into adjacent or crossing yarns is attained. This use of the rasping-profile needle is exemplified below. The loom equipment is the same as that previously described in connection with the felting of non-woven fabrics.

Example 16 The needle-loom is equipped with the etched needles of Example 1. A Shetland tweed type of fabric with a 2 x 2 twill construction and having a weave count of 32 x 30 is woven from a yarn containing a stock blend of 20% wool and 80% 3 denier, 2 /2 inch length polyacrylonitrile staple. The fiber is spun into an 18/2 cotton count yarn. The singles have a Z twist ofll turns per inch and are plyed with an S twist of turns per inch. A portion of the yarn is dyed brown before weaving, so that the woven fabric consists of a pattern of Example 17 A womans sweater is knitted on a 12-cut circular knitting machine from a yarn of polyacrylonitrile staple. The fiber is spun into a 2/24 worsted count yarn from 3 denier staple, 2%"lon'g. The singles are twisted 10 turns 2 to the inch. The ply contains 6% turns 8 to the inch. The sweater is dyed yellow. It is then fed to the needle loom as equipped with the etched needles of Ex-' ample 1 for a total of 28 passes. The sweater is turned inside out after each pass. This is a total of about 3800 punchings per square inch. The covering power of the needle-punched sweater is increased so that whereas when ultra violet light is directed at the samples the original sweater transmits 6.3% of the light while the needled sweater transmits only 0.4% as recorded on a photo-electric cell. The needle-punched sweater. is fulled despite the fact that the yarn from which it is knitted contains no wool. It has a softer hand, greater bulk'and is less sleazy as compared with its condition before punching. When the loom is equipped with the unetched needles of Example 1, many yarnsof fabric are rent without fulling after only a few passes of the fabric through the loom.

A rasping-profile needle is the preferred type of needle in the fulling process as exemplified in Examples 16 and 17 above. Where the profile discontinuity is not essentially hookless, i. e., where a tangent to the discontinuity, progressed in either direction from the point wherein it is parallel to the longitudinal axis of the needle, sweeps out an angle of more than about the needle tends to rend the fabric yarns causing the fabric to be weakened and in some cases disintegrated.

Since fulling by multiple needling of woven andknitted fabrics is not feasible with barbed needles, effects formerly unattainable are made possible by the raspingprofile needle structure. The effectsattainable by use of the rasping-profile needle in fulling woven and knitted fabrics include removal of fabric wrinkles, uniformity, surface levelness, improved hand, nap and an increase in fabric bulk, covering power, stiffness and body.

The cross-sectional shape of the blade of the needle of the present invention is not critical. The needles exemplified have a blade of triangular cross-section.

However, other shapes such asv round, flat, elliptical,

square, rectangular, hexagonal or the like, may be used. It is preferred, in any case, that ,the cross-sectional dimension of the blade D be maintained at as low a value as possible consonant with strength requirements. Usually a blade having a cross-sectional dimension of about 0.050 inch is satisfactory. Fabrics of very fine, relatively delicate yarn, especially where the fabric has a tight weave may require a somewhat finer needle. For most household clothing and industrial fabrics a dimension D within the range of about 0.020 to about 0.040 inch is adequate. However,-at times a dimension D as low as about 0.010 inch is advisable. Since the piercing end of the blade terminates in a point it is obvious that the blade: will be tapered at its piercing end. If desired the entire blade section may be so tapered.

The hookless-break which produces the profile discontinuity along the blade of the rasping needle is preferably of the notch variety. While the notch depth, dimension B as previously defined, may vary widely, depending upon the type of function to Which it is to be applied and the properties of the fabricfed to the needle loom, a depth Within the limits of about 0.002 to about 0.012

inch is generally employed. Usually it is maintainedwithin the limits of about 0.002 and 0.008 inch. In general the deeper notches are satisfactory with coarse weaves of higher denier, high twist, tough yarn. Tight weaves of low denier, delicate, low twist yarns make choice of a needle with a blade of shallower notches desirable. Where the profile discontinuity is created by a hookless protuberance, it is preferably no greater than about 0.001 inch whether or not it is in combination with anotch.

The profile discontinuity of the needle blade is disposed substantially horizontally across the blade when the needle is held vertical. Where a notch produces defined previously, be at least 90, although notches of smaller angles are sometimes operable. A range of notch.

barbed blade bysuspending the needle so that its blade is immersed. in. an acid solution. The. etching process tends to? remove Jthe hook of the. barb while usually decreasing the cross-sectional dimension D, the maximum protuberance A, the notch depthB and the overall length of the blade. The notchangle or increases. Other general etfects of the etching process include a sharpening of the needle point and a sharpening of-any edgesalong the blade length. The usual etching bath is a 37%' so1utionof hydrochloric acid in water. Other acidsmay be employed in place of thehydrochloric. In the etching procedure, spent acid is preferably: replaced with fresh acid at intervals. barbed needle to a rasping-profile needlewill depend'on many factors such as'th'e etching=bath composition, the material of needle' construction,the dimensions of the blade of the unetched needle and the like. The period necessary can be approximated by comparing with-the period required for a Torrington No. 25 regular barb steel needle etched with the 37 hydrochloric acid using about 4 cc. of acid per needle, replaced at intervals of about 2 /3 hours. This needle, commonly designated as 15 x 18 x 25- X 3 /2 regular barb is manufactured by the Torrington'Comp-any of Torrington, Connecticut; Its. overall lengthis 3 /2 inches. point which tapers to an equilateral triangular cross-sectional dimensionof-0.039 inch.

barbs on an edge. The first and last barbs are 0.25 and 1 inch respectively from the point. The blade (i. e., the working section including the point) is about 1.1 inches in length. The removal of the protruding hook to bring it within the definition of a rasping-profile needle requires a minimum of about4 hours etching at room temperature. In general, such needlesetched for a period of from about 4 to about 16 hours give satisfactory results. Such treatment reduces the cross-sectional dimension D about 30 to 40%. The protruding discontinuity (dimension A) disappears at about 4 hours. The preferred needles are those treated from 6 to hours. Under'these conditions the notch-angle or increasesto within about 110 to about 160. The notch depth B is within the range-of about 0.002 to 0.008 inch. The length of the blade decreases about 3% after etching for 7 hours as described .above. The optimum etching period for anyupa'rticular needle can be approximated by a compari-- More exactfigures can be obtained The period necessary to transform a" It has a round-sharp It contains 9 barbs staggered evenly along the blade about 0.25 inch apart, 3

The pro file discontinuities may be introduced by spot welding,

UT grinding-polishing,.firing, sand blasting, swaging, liquid honing, or other mechanical means. The notches may be introduced by striking the. needle-normal to its longitudinal axis with a sharpv instrument, by filing and the like.

- While metal, specifically steel, is the preferred material of construction, other substances such as glass, ceramic, plastic or the like mayflikewise be employed. A plastic needle makes production of rasping-profile needles possibleby extrusion or injection molding, an extremely fast and inexpensive method.

While the rasping-profile needle of this invention is particularly useful inthe forming of coherent felt-like products containing a substantial proportion of retractable synthetic filaments and in the fulling of fabrics by multiple needling',.it.will be obvious that many other uses are possible. Thus it may be employed for loosely locking an unwoven ,batt with or without shrinkage. It may be used'to edge a batt, a woven or knitted fabric or to create novel designs in such materials. It is useful also in the making of endless belts by joining, i. e., an interweaving of two ends of the same fabric followed by fulling to strengthen the join, in the manufacture of papermakers felt and the like.

Typical examples of materials in the production of which rasping-profileneedles are valuable include natural or synthetic (or mixtures thereof) woven and non-woven products such as filter fabrics for both gas and liquid filtrations, papermake'rs felts, polishing felts and fabrics, insulation, sound absorbe'nts, blankets, wicking felts,

shock mounting felts, conveyor beltings, roll coverings,

Sanforizing blankets, the fibrous component of plastic laminates and the like. Examples of household products are apparel, such as sweaters, suitings, hosiery, overcoatings, underwear, shitting and'blouse fabrics, headwear, carpets and their underliners, upholstery fabrics, draperies, boot linings and the like.

Many other modifications within the scope of the above, invention -will be apparent to those skilled in the art without a departure from the inventive concept.

What is claimed is:

l. A needle whose profile continuity is broken along its body by at least one hookless break, said break being a discontinuity ofsuch shape that as the tangent to the discontinuity in the plane of the profile is progressed in either direction from the position where it is parallel to the longitudinal axis of the needle, it will sweep out an arc of no more, than about without disrupting tangential contact.

2. The needle of claim 1 wherein the discontinuity is a protuberance.

3. The needle of claim 1 wherein the discontinuity comprises a curved notch and a protuberance.

4. The-needle. of claim 1' wherein the discontinuity isa notch.

5. The needle of claim 4 wherein the notch angle alpha, as exemplified by Figure 2a, is at least 90.

6. The needle of claim. 4 wherein the profile of the notch is-a smooth curve.

7. A needlehaving an irregular profile, the discon tinuity being an abrupt, hookless break in the form of a notch, where-the notchangle alpha, as exemplified by Figure Za, is. greater, than 90.

References Cited in the file of this patent UNITED STATES PATENTS 2,015,609 Swinglehurst Sept. 29, 1935 2,327,416 Foster Aug. 24, 1943 2,349,086 Foster May 16, 1944 2,635,322 McDermott Apr. 21, 1953 2,678,484 Brown May 18, 1954 2,696,035 Foster Dec. 7, 1954 UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No 2,857,650 October 28, 1958 Herbert G, Lauterbaoh It is hereby certified that error appears in the-printed specification of the above numbered patent requiring correction and that the said Letters Patent should read as corrected below.

Column 6, line '06, for "higher" read high Signed and sealed this 24th day of March 1959.

(SEAL) Attest:

KARL H. AXLINE ROBERT C. WATSON Attesting Oflicer Commissioner of Patents 

